By 2020, 70% of people living with HIV in the United States will be ?50 years of age due, in large part, to improved clinical care, more efficacious antiretroviral therapy regimens, and the increasing number of persons newly diagnosed with HIV ?50 years of age. An estimated 37% of sexually active older people living with HIV (OPLWH) continue to engage in HIV transmission sexual behaviors. In spite of repeated calls for secondary prevention interventions to reduce condomless sex in OPLWH, no age-appropriate, evidence-based secondary prevention interventions exist for this group. Many OPLWH cannot engage in face-to-face secondary prevention services because of HIV- and age-related stigma, comorbid mental and physical health conditions that complicate travel to venues in which HIV prevention interventions are delivered, or geographic isolation. High rates of depression and neurocognitive impairment in OPLWH may further complicate engagement in, and reduce benefits of, interventions that aim to reduce HIV transmissions in this group. The proposed study is a randomized controlled trial of a 5-session telephone-administered motivational interviewing plus behavioral skills training (teleMI+BST) intervention to reduce condomless sex in HIV-positive adults 50-plus years of age. A geographically and ethnically/racially diverse sample of 336 OPLWH will be recruited across the U.S. through community-based organizations that serve people living with HIV, rural networks of HIV social service providers, advertisements placed in HIV-related magazines and websites, and online dating forums. Eligible persons will be randomly assigned to receive either a 5-session teleMI+BST intervention or an attention equivalent 5-session telephone-administered coping effectiveness training (teleCET) control intervention. Study therapists will be community-based HIV social service providers located in Portland, OR. Self- administered questionnaires will assess demographic characteristics, and condom use knowledge, beliefs, attitudes, and skills, while a brief telephone interview will assess sexual behavior, substance use, and psychiatric symptoms. A telephone-administered neurocognitive assessment will also be conducted at baseline. Study Aim 1 will test the efficacy of teleMI+BST to reduce occasions of non-condom protected anal and vaginal intercourse with HIV-negative or unknown HIV serostatus partners and examine psychosocial mediators of intervention efficacy. Study Aim 2 will test the efficacy of teleMI+BST to reduce depressive symptoms in mildly depressed participants. Study Aim 3 will test the moderating effect of baseline depressive symptom severity on teleMI+BST efficacy. Additional exploratory analyses will examine the impact of neurocognitive functioning, VL, and pre-exposure prophylaxis (PrEP) use by participants' sexual partners on teleMI+BST efficacy. This study may yield an evidence-based, person-centered intervention that meets the unique sexual relationship and health needs of OPLWH and reduces the transmission of HIV to their HIV- negative sexual partners.